The present invention relates to the field of perfumery. More particularly, it relates to the use, in a perfuming composition, of a fatty alcohol obtainable by a process of reducing the carbonyl function of a vegetable or animal oil with appropriate quantities of polymethyl-hydroxysiloxane.
The use of fatty alcohols in cosmetic compositions is well known from the prior art, for example from patent application WO 96/37285, which discloses the use of fatty alcohols in emulsifying cosmetic compositions, or from application WO 97/01326, which describes cream compositions comprising in particular, from among the hydrophobic agents used, fatty alcohols. In this type of application, the fatty alcohols used act as a structurant in order to promote the Theological characteristics of the composition. More generally, the long-chain fatty alcohols are therefore used as emollients in cosmetic or pharmaceutical compositions, as structurants in emulsions or as stabilisers in an emulsifying system. They are frequently found in compositions for hair care products, in moisturising creams for dry skin and in pharmaceutical bases.
However, to our knowledge, these alcohols have never been used in perfuming compositions.
We discovered, quite surprisingly, that the fatty alcohols obtainable by reducing the carbonyl function of a vegetable or animal oil of natural origin could advantageously be used in perfuming compositions. In particular, and according to a preferred embodiment of the invention, these fatty alcohols can quite unexpectedly act as a solvent or co-solvent in these perfuming compositions.
The use of the fatty alcohols according to the invention in perfuming compositions, in particular as solubilisers of the perfuming ingredients which are a constituent of these compositions, has numerous advantages. In the preparation of perfumes, eaux de toilette and eaux de Cologne for example, the use of solvents such as ethanol or isopropanol is very common. Ethanol provides good solubilisation of the perfuming ingredients to which the perfumer has recourse. The perfumes and eaux de toilette found on the market generally contain between 50% and 95% ethanol by volume. However, this type of solvent commonly used in perfumes or other perfuming compositions can be subject to use restrictions by the legislation of certain countries. For this reason, the attempt is being made to replace this type of solvent in the aforementioned products. We have discovered that the fatty alcohols derived from vegetable or animal oils can advantageously replace, in whole or in part, the aforementioned solvents commonly used in perfumery. In fact, these products of natural origin easily solubilise any type of perfuming ingredient.
Other advantages will become apparent from the description and the examples.
The fatty alcohols according to the present invention are obtainable by reducing the carbonyl function of a vegetable or animal oil. This process consists in reacting the said oil with appropriate quantities of polymethylhydroxysiloxane (PMHS) in the presence of a catalytic system prepared from a metal salt or complex and a reducing agent, followed by hydrolysis of the resulting siloxane by means of a basic agent and the separation and purification of the desired alcohol thus formed. The precise process for the preparation of these alcohols is described in U.S. Pat. No. 5,831,133 and in International patent application WO 99/12877. The first of these documents describes e.g. an original process for the reduction of, in particular, esters by polymethylhydroxysiloxane, catalysed by soluble hydrides of metals such as zinc, manganese or iron. PMHS is a cheap and abundant co-product in the silicone industry. Stable in air and water, it is particularly easy to use in any polyvalent reactor, whereas the use of hydrides such as LiAlH4 and NaBH4 used in xe2x80x9cconventionalxe2x80x9d reductions necessitates working in a dry reactor which has been rendered inert.
One of the remarkable properties of this technology is that it allows the direct reduction of the vegetable and animal oils with excellent yields. This reaction is catalysed preferably by soluble zinc hydrides produced e.g. by reaction between a soluble zinc carboxylate and a hydrogen donor such as NaBH4.
The process described in WO 99/12877 is also suitable for the preparation of the fatty alcohols used according to the present invention and it has the additional advantage of dispensing with the use of NaBH4.
The contents of U.S. Pat. No. 5,831,133 and application WO 99/12877 and the teachings of these documents in relation to the reduction of the appropriate natural oils and the application of these processes to this reduction are included herein by reference.
These processes are advantageously used to prepare the fatty alcohols according to the invention because they enable the structure and the stereochemistry of the starting products, namely the vegetable or animal oils, to be preserved. In other words, if one compares the reduction described in the documents included herein by reference with the conventional catalytic hydrogenation commonly used for reduction of the fatty animal or vegetable oils, this latter necessitates their prior transesterification into the corresponding methyl ester and is carried out on a large scale under drastic temperature and pressure conditions, which affects the position and the stereochemistry of the double bonds and, consequently, the natural character of the product. In constrast, the processes described in U.S. Pat. No. 5,831,133 and WO 99/12877 enable these to be preserved, with the result that the reaction product, i.e. the fatty alcohol, has the same stereochemistry as the initial animal or vegetable oil, thus preserving its natural form, which represents a considerable advantage. We also discovered that the fatty alcohols thus obtained could have properties which are highly advantageous to the object of the invention.
The present invention thus relates to the use, in a perfuming composition, of a fatty alcohol obtainable by a process of reducing the carbonyl function of a vegetable or animal oil, said process consisting in reacting the said oil with appropriate quantities of PMHS in the presence of a catalytic system prepared from a metal salt or complex and a reducing agent, followed by hydrolysis of the resulting siloxane by means of a basic agent and the separation and purification of the desired alcohol thus formed.
Of the fatty alcohols used according to the invention, the preferred ones are those which constitute the product of the reduction of a vegetable oil selected from the group comprising olive oil, sunflower oil, palm oil, cottonseed oil, colza oil, soya oil, sesame oil, jojoba oil or coconut oil.
Apart from the fact that they preserve the position and the stereochemistry of the double bonds of the natural oils from which they are derived, the fatty alcohols according to the invention have further advantages when used in a perfuming composition. For example, these compounds impart to the composition to which they are added a soft, non-greasy feel when applied to the skin, whereas a conventional solvent such as ethanol has the tendency to dry out the skin.
The alcohols according to the invention are used to particular advantage not only in perfumes, eaux de Cologne and eaux de toilette, but also in applications such as perfumed oils for the skin or hair.
It goes without saying that the use of the fatty alcohols derived from vegetable or animal oils according to the invention is not limited to the aforementioned products, but is also suitable for other perfumery applications, in particular in functional perfumery. Examples of this type of application include shower and bath gels, shampoos, deodorants and anti-perspirants. Owing to their natural character, their emollient properties, their non-greasy nature, their softness to the touch and their penetration power, the natural alcohols according to the present invention are therefore usable in numerous applications.
According to a preferred embodiment of the invention, the natural fatty alcohols produced from the reduction of a vegetable or animal oil act as a solvent or co-solvent in a perfuming composition. In fact, these constituents advantageously solubilise all types of perfuming ingredients.
The fatty alcohols according to the invention can be used as solvents both in a perfuming composition comprising, in addition to the perfume, additives and adjuvants depending upon the final application, and in a concentrated perfume or base composition comprising only perfuming starting materials. The solvents generally used in these latter compositions, namely diethyl phthalate or dipropylene glycol, are suitable solvents for dissolving all the starting materials, both liquid and solid. However, we discovered, quite surprisingly, that the fatty alcohols according to the invention were also able to dissolve these substances and thus replace in particular the diethyl phthalate or dipropylene glycol.
The invention also relates to a perfuming composition, characterised in that it contains a fatty alcohol obtainable by the reduction process described in U.S. Pat. No. 5,831,133 or WO 99/12877.
In a particularly advantageous embodiment of the invention, the natural fatty alcohol present in a perfuming composition according to the invention advantageously replaces, in whole or in part, the solvent generally used. It therefore acts either as sole solvent or as co-solvent in combination with ethyl alcohol, isododecane or other solvents known to the skilled person and used in this type of composition. In this way, the proportion of ethanol, for example, can be reduced, even eliminated.
Furthermore, in applications such as perfumed massage oils which contain, in addition to the perfuming ingredients, paraffin oil (or an equivalent), the compounds according to the invention, owing to their structure, advantageously enable the perfume to be solubilised in the oil. This property of the fatty alcohols renders them highly useful in any type of perfuming composition containing an oil such as paraffin oil. Indeed, they preserve the properties of the natural oils from which they are derived whilst solubilising all the ingredients of the composition.
The perfuming composition according to the invention can contain, in addition to a fatty alcohol derived from an oil of natural origin and a perfuming ingredient, a volatile agent.
Preferred volatile agents in the perfuming composition according to the invention are the volatile hydrocarbons, the volatile silicone oils, isopentane or a mixture of these compounds. These are given as non-limiting examples, the skilled person being capable of selecting appropriate volatile agents other than those mentioned.
The skilled person is also capable of selecting one or more perfuming ingredients according to the nature of the product to be perfumed and the desired olfactory effect. These perfuming ingredients can belong to classes as varied as the alcohols, aldehydes, ketones, esters, ethers, acetates, nitrites, terpene hydrocarbons, nitrogenous or sulphurous heterocyclic compounds and also essential oils of natural or synthetic origin. Many of these ingredients are also listed in works of reference such as the book by S. Arctander, Perfume and Flavor Chemicals, 1969, Montclair, N.J., USA, or its more recent versions, or in other works of a similar nature.
Apart from the different types of ingredient mentioned, the perfuming composition according to the invention can also comprise other adjuvants such as antioxydants, chelating agents or propellants, the skilled person being capable of selecting them on the basis of the desired final application or the type of packaging used for the composition according to the invention.
Furthermore, according to a preferred embodiment of the invention, the perfuming composition comprises a fatty alcohol as mentioned hereinabove in combination with a natural oil (for example olive oil or sunflower oil). Thus combined, we discovered that the fatty alcohols obtained by reduction of a vegetable or animal oil of natural origin were, in fact, capable of reducing the greasy, sticky effect on the skin of the compositions containing fatty oils of natural origin. The presence of isopentane or other volatile hydrocarbons also has this effect.
The proportions in which the compounds according to the invention can be incorporated into the different aforementioned products varies within a wide range of values. These values depend on the role played by the fatty alcohols in the composition, i.e sole solvent or co-solvent. They also depend on the proportion of perfuming ingredient to be solubilised, i.e. indirectly on the nature of the perfuming composition and the desired olfactory effect.
As an example, typical proportions are in the order of 0.5% to 80%, preferably 10% to 40%, of fatty alcohol relative to the weight of perfuming composition into which it is incorporated.
By reason of their emollient properties, their non-greasy nature and their soft feel, they render the perfume or perfuming composition very pleasant to the touch when applied to the skin.
The invention will now be described in further detail in the following examples in which the abbreviations have the usual meaning in the art.